The yam frequently grows to the enormous size of forty or fifty pounds weight, but in this large state it is coarse-flavored and fibrous.

An acre of land is capable of producing 41/2 tons of yams, and the same quantity of sweet potatoes, within the twelve months, or nine tons per acre for both, being nearly as much as the return obtained at home in the cultivation of potatoes; and I have the authority of all analytical chemists for saying that in point of value, as an article of food, the superiority is as two to one in favor of the tropical roots.

The kidney-rooted yam (D. pentaphylla), is indigenous to the Polynesian islands, and is sometimes cultivated for its roots.  It is called kawaii in the Feejee islands. D. bulbifera, a native of the East, is also abundantly naturalised in the Polynesian islands, but is not considered edible.

There are seven or eight kinds of yams grown in India.  Two are of a remarkably fine flavor, one weighing as much as eighteen pounds, the other three pounds.  These are found in the Tartar country.

COCOS OR EDDOES

Arum esculentum.—­This root has not hitherto been considered of sufficient importance to demand particular care in its cultivation, except by those who are engaged in agricultural pursuits, and derive their subsistence from the production of the soil.  But though the cultivation of the root is almost unknown to the higher classes in society, and little regarded by planters in the colonies, it is a most valuable article of consumption.  Amongst the laboring population it is the principal dependence for a supply of food.  Long droughts may disappoint the hopes of the yam crop, storms and blight may destroy the plantain walks, but neither dry or wet weather materially injure the coco; it will always make some return, and though it may not afford a plentiful crop, it will yield a sufficiency until a supply can be had from other sources.  For this reason the laborer in the West Indies always takes care to put in a good plant of cocos to his provision ground as a stand by, and knowing their value, is perhaps the only person who bestows any degree of care or attention upon them.  Previous to their emancipation, whole families of negroes lived upon the produce of one provision ground, and the coco formed the main article of their support.  Where the soil is congenial to the white and black Bourbon coco, the labor of one industrious person once a fortnight will raise a supply sufficient for the consumption of a family of six or seven persons.  The coco begins to bear after the first year, and with common care and cultivation the same plant ought to give annually two or three returns for several years.  In Jamaica, a disease something similar to that affecting the potato, has been found injurious to the coco root.  This disease, which has baffled all inquiry as to its origin, affects the plants in and after the second